Researchers in Milan discover new silicon-based technology

MILAN, Italy, March 16 — A team of researchers in Milan announced the creation of a new technology aimed at improving the performance of different materials deposited on silicon.

The "Scaling hetero-epitaxy from layers to three-dimensional crystals" technology, developed by a team of researchers from Milan-Bicocca University, Milan Politecnico University, Swiss Federal Institute of Technology in Zurich and CSEM (Swiss center of microelectronics and microtechnologies), came from observing the secret of a perfect material – not subject to ruptures, distortion or other imperfections – is to grow with a good patterning.

"This new technology is grounded on the patterning of silicon substrates in order to deposit other semiconductors, which are different in lattice parameters and thermal properties," Leo Miglio, one of the discovery's authors and a physics professor at Milan-Bicocca University, told Xinhua.

Silicon substrates are abundant, cheap and well-known, he pointed out, so that the integration of high-cost or rare materials, such as germanium, gallium arsenide and silicon carbide will allow devices with lower cost and better performances.

"The deep patterning of the silicon substrates in pillars allows the selected deposition of different semiconductors on top of the pillars, when suitable growth conditions are selected in the deposition equipment," Miglio said.

In particular, large arrays of uniform micro-crystals tessellating the all film are produced when a fast deposition modality is obtained, he added.

The Italian-Swiss joint result will allow the development of a new technological platform, the scientist said, adding "applications are envisaged in thick film devices, such as photovoltaic, triple junction, cells, X-ray imagine detectors for medical applications and other electronics devices."

Applications shall include lighter and highly efficient solar cells for satellites, sensors monitoring operations in laparoscopy with very low doses of X-rays, and cheaper electronics devices to manage motor vehicles and alternative energies.

Savings for photovoltaic cells are estimated at around 15-20 percent for each cell, while regarding cells used to power satellites, costs would be even lower thanks to the cells' lightness with a subsequent minor fuel consumption.

The discovery is an important result also due to the fact silicon had been considered recently "out of fashion" compared to other materials such as graphene, while the Italian-Swiss team has now shown its advanced utility, the professor noted. (PNA/Xinhua) DCT/LAM/ebp